Payload interposer (PIP) system and control software

Abstract

A payload interposer (PIP) system and its control software provide an interface between a space vehicle and a payload. The PIP board facilitates power and communications between a command and data handler (CDH) of the space vehicle and the payload. A microcontroller of the PIP board may control operation of the payload, format messages between the space vehicle and the payload, and extract data from the payload for downlink via the space vehicle.

The invention claimed is: 
     
       1. A payload interposer (PIP) system, comprising:
 a space vehicle comprising a command and data handler (CDH); 
 a payload; and 
 a payload interposer (PIP) board comprising a microcontroller, the PIP board facilitating power and communications between the space vehicle and the payload, wherein control software for the microcontroller is configured to:
 control operation of the payload, 
 format messages between the space vehicle and the payload, and 
 extract data from the payload for downlink via the space vehicle, wherein 
 
 the microcontroller of the PIP board is a full participant in a network of the space vehicle and implements functionality common to all boards of the space vehicle network via a library defined in a software development kit (SDK) for payload developers. 
 
     
     
       2. The PIP system of  claim 1 , wherein
 the microcontroller is configured to cause the PIP board to operate in a maintenance mode or an operational mode depending on a command from the space vehicle, a ground station, or both, 
 power to the payload is disabled in maintenance mode, and 
 the payload is powered in operational mode. 
 
     
     
       3. The PIP system of  claim 1 , wherein the PIP board comprises a file system and the microcontroller first stages data to be sent to the payload by the space vehicle or received from the payload by the space vehicle in the file system. 
     
     
       4. The PIP system of  claim 1 , wherein the CDH is configured to schedule payload activities based on a current space vehicle position and/or ground positions of interest that are loaded into a CDH configuration file. 
     
     
       5. The PIP system of  claim 4 , wherein
 the CDH is configured to instruct the PIP board to power on and initialize the payload when the space vehicle reaches a predetermined position, the space vehicle is approaching a target pass, or both, and 
 the CDH configuration file comprises data for each target for latitude, longitude, minimum elevation, whether to operate the payload, lead time, and pointing. 
 
     
     
       6. The PIP system of  claim 4 , wherein the CDH is configured to cause the space vehicle to perform nadir pointing, zenith pointing, target pointing, anti-target pointing, or no pointing for a given target based on pointing data in the CDH configuration file. 
     
     
       7. The PIP system of  claim 1 , wherein the CDH is configured to reset, and control power to, the PIP board and the payload. 
     
     
       8. The PIP system of  claim 1 , wherein the CDH is configured to cause the PIP board to switch between maintenance and operational modes, enable/disable power to the payload, enable/disable sequencing of payload commands, and provide commands for managing payload data files. 
     
     
       9. The PIP system of  claim 1 , wherein the microcontroller is configured to support commands from the space vehicle for reset, file uplink, file downlink, code reprogramming, and logging. 
     
     
       10. The PIP system of  claim 1 , wherein the PIP board is configured to:
 receive state-of-health (SOH) data from the payload; 
 append the payload SOH data to SOH data for the PIP board, forming combined SPH data; and 
 send the combined SOH data to the space vehicle to be downlinked to a ground station. 
 
     
     
       11. The PIP system of  claim 1 , wherein the microcontroller is configured to:
 perform command sequencing to send commands to, and receive responses from, the payload; 
 send commands in serial by sending a next command after a response to a previous command is received; and 
 stop operation of a command-response list when an expected response to a command is not received. 
 
     
     
       12. The PIP system of  claim 11 , wherein each command and response comprises a header, a message identifier, a number of data bytes, packet data, and a cyclical redundancy check (CRC). 
     
     
       13. The PIP system of  claim 1 , wherein the PIP board comprises a PIP configuration file that defines formats of command messages sent from the PIP board to the payload, response messages sent by the payload, payload data, space vehicle position, velocity, and time (PVT) messages, time messages, and payload state-of-health (SOH) messages. 
     
     
       14. The PIP system of  claim 1 , wherein the SDK library functionality comprises generic command handlers that allow the microcontroller of the PIP board to act on commands from a ground segment of space vehicle CDH, short and long watchdogs protecting against hardware and software failure on the PIP board microcontroller, an internal time-of-day clock operating in a predetermined epoch, multiple code bank support that allows for on-orbit code updates and fallback in event of failure, file uplink and downlink with transfer and reassembly of files at their destination, lossless file compression and decompression, configuration file support, logging of system errors and forwarding of error logs to the CDH for later downlink, or any combination thereof. 
     
     
       15. The PIP system of  claim 1 , wherein
 the CDH comprises a configuration file, and 
 the CDH configuration file is configured to cause the CDH to enable/disable payload operations, provide an amount of time to conduct payload operations, provide an interval between transmissions of global positioning system (GPS) information between the CDH and the PIP board, provide an interval between transmissions of time information between the CDH and the PIP board, and provide target information. 
 
     
     
       16. A payload interposer (PIP) board, comprising:
 memory storing computer program instructions; and 
 a microcontroller configured to execute the computer program instructions, wherein the instructions are configured to cause the microcontroller to:
 control operation of a payload, 
 format messages between a space vehicle and the payload, and 
 extract data from the payload for downlink via the space vehicle, 
 perform command sequencing to send commands to, and receive responses from, the payload, 
 send commands in serial by sending a next command after a response to a previous command is received, and 
 stop operation of a command-response list when an expected response to a command is not received. 
 
 
     
     
       17. The PIP board of  claim 16 , wherein the instructions are further configured to cause the microcontroller to:
 stage data in a file system of the PIP board before sending the data from the payload to the space vehicle, from the space vehicle to the payload, or both; and 
 support commands from the space vehicle for reset, file uplink, file downlink, code reprogramming, and logging. 
 
     
     
       18. A space vehicle, comprising:
 a command and data handler (CDH) configured to:
 cause a payload interposer (PIP) board to switch between maintenance and operational modes, enable/disable power to a payload, enable/disable sequencing of payload commands, and provide commands for managing payload data files, 
 schedule activities of the payload based on a current space vehicle position and/or ground positions of interest that are loaded into a CDH configuration file, and 
 instruct the PIP board to power on and initialize the payload when the space vehicle reaches a predetermined position, the space vehicle is approaching a target pass, or both, wherein 
 
 the CDH configuration file comprises data for each target for latitude, longitude, minimum elevation, whether to operate the payload, lead time, and pointing.